What was found
DURING CRUISE AT FL330, THE NR 1 AND NR 4 ENGINES FLAMED OUT SIMULTANEOUSLY. RESTART WAS SUCCESSFUL AND THE FLIGHT CONTINUED TO NRT WITHOUT FURTHER INCIDENT. MAINTENANCE PERFORMED CROSS FEED VALVE OPERATIONAL CHECK, FUEL TRANSFER VALVE CROSS FEED MANIFOLD IN FUEL FLOW CHECK AND FOD CHECK. CHECKS WERE NORMAL AND RUNUP OF ALL FOUR ENGINES REVEALED NO DISCREPANCIES. REPLACED ALL FOUR ENGINE FILTERS AND AIRCRAFT RETURNED TO SERVICE.